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ADVANCED 3D VISUALIZATION TECHNIQUES 
COLIN WARE 
Faculty of Computer Science, P.O. Box 4400 
University of New Brunswick, Fredericton, N.B. E3B 5A3 
email: cware @UNB.ca 
ABSTRACT 
Highly interactive 3D graphics is on the threshold of becoming affordable and this opens the door to a whole new range 
of applications. However, while a well defined set of interaction techniques exists for the 2D screen environment, the 
3D user interface is evolving rapidly. This paper focuses on the user interface to 3D graphics environments. Novel 
input devices, 3D widgets, Fly-By techniques, Stereo displays, and Fish Tank virtual reality are discussed within the 
framework of J.J. Gibson's theory of affordances. 
L'interface utilisateur pour la visualisation en 3D 
Le graphisme en 3D hautement interactif est sur le point de devenir abordable et cela ouvre la porte vers toute une 
panoplie de nouvelles applications. Néanmoins, alors qu'il existe un ensemble bien défini de techniques pour 
l'environnement de l'écran en 2D, l'interface utilisateur en 3Dévolue rapidement. Cet expose va se concentrer sur 
l'interface utilisateur pour un environnement graphique en 3D. Des nouveaux périphériques d'entrées, les widgets en 3D, 
: z . £ 2.3 . ^ . 2 . A > 
les techniques de survol, la représentation en stéreo, la réalite virtuelle vont etre discutés à travers la notion théorique de 
J.J. Gibson, 'affordances'. 
KEY WORDS: 3D views, Geographical Information System, Visual data display. 
highway planning, appreciating sight lines in urban 
planning or forestry, and representing ore bodies in 
1. INTRODUCTION mining applications are all areas where 3D 
visualization can help. In general 3D visualization is 
useful where the structures to be understood are 
physically displaced in the vertical direction and this 
displacement is critical to the application. Three 
dimensional representations will become even more 
important as GISs evolve into GCADS (Geographical 
Computer Aided Design Systems). 
The great contribution of Geographical Information 
Systems can be seen as an advance from one 
dimensional information, usually tables of scalar 
coordinates, to two dimensional information - a map 
linked to a data base. The methods for manipulating 
maps are well established and they consist for the most 
part of scale and translate operations for positioning, as 
well as point, line and area specification for data input. 
A third dimension is added to a limited extent in the 
form of overlays, providing layers of information. 
However, overlays are a convention for representation, 
in general the layer does not denote scalar height 
information. 
To realize the potential of 3D GIS a number of 
problems must be solved. In particular, there are new 
data visualization and manipulation techniques to be 
invented (after all true 3D output devices are still 
many years away). While 2D GIS systems have 
borrowed heavily from the paper maps that preceded 
them, and which are often the most useful product. 3D 
GIS has no such antecedents, unless it is the model of 
the landscape architect. There are other problems 
related to the need for a the database to support true 3D 
visualization and to retain volumetric information, and 
we need to support true 3D queries into that database. 
These database issues are beyond the scope of this 
This may all be about to change as high performance 
3D graphics systems become commonplace. There are 
increasing numbers of people experimenting with 3D 
representations of data and it is becoming clear that this 
is useful and practical for many applications. For 
example, understanding the surface topography in 
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